Temperature-control system



May 31, 1927,

1,630,755 H. MILKER TEMPERATURE CONTROL SYSTEM 4 laheets-Sheetl Filed May e, 1924 HN l] m i i i x Ulmlllulwllulif l May 31, 1927.. 1,630,755

H. MILKER TEMPERATURE CONTROL SYSTEM Filed May 6, 1924 4 Sheets-Sheet 2 wm f H. MILKER l TEMPERATURE CONTROL SYSTEM 'FiledMay 6. 1924 `4 spons-sheet 5 VENTOR YQ/MMM 1927. May 31 H. MILKER TEMPERATURE CONTROL `SYSTEM Filed May 6, 1924 4 Sheets-$heet 4 lll vPatented May 31, 1927.

UNITED STATES i 1,630,155 PATENT oFFlcE.

HERBERT MILKER, QUEENS, NEW YORK, ASSIGNOR T0 AMERICAN SCHAEFFEB & BUDENBERG CORPORATION, A CORPORATION ,013" NEW YORK.

TEMPERATURE-CONTROL SYSTEM.

Application led May 6, 1924. Serial No. 711,351,

pressure cause air valve .clogging diiliculties` and similarly the impurities in suspension or solution in a water pressure system give erratic and unreliable regulation.

The' object of this invention is to overcome these objections by dis ensing with the separate auxiliary motive uid and to provide al system in which the heating medium itself, such as steam, operates the heat regulating valve. The resulting operation is accurate and reliable giving an exact control of the heat supply valve so that the system is thoroughly practical and is unlimited in its field of use. ,d

ln the accompanying Adrawings illustrating the inventionf I Fig.Y 1 is a diagrammatic view of'a control system showing one embodiment of the invention.

Fig. 2 is avertical sectional view of a portion of the apparatus shown in Fig. 1.

Fig. 3 is a vertical sectional View of another portion of the apparatus shown in Fig. 1.

Fig. Il is a vertical sectional View illustrating a modification .of the apparatus shown in Fig. 2. y

Fig. 5 is a sectional view showing a modified form of thermostatic bulb and Figs.' 6 and 7 are cross sectional views on the lines 6-6 and 7-7 of Fig. 5.

lin the embodiment of the invention illustrated in the drawings a chamber, such for instance as the tank 6, containing a liquid 7. is to be heated by a steam supply from pipe S, through regulating valve 9 and piplng l0. The steam at ll is shown as dis charging intothe liquid 7 but obviously the steam might be simply circulated through heating coils provided with a return to the source ot heat. y y f llfithin the fluid being heated is placed a therinostaticl bidh 12, and the changes ot' temperature of this bulb control the heatl supply to the liquid to maintain a desired temperature of the iiuid being heated.

In the system of this invention -the movement of the valve 9 to regulate the supply in response to changes of temperature at the bulb 12 is eii'ected by the steam supply itself. When there is a rise of temperature at the bulb 12 steam from the line 8 is used as the operating means of valve 9 to actuate the valve so as to decrease the supply of steam to the tank. `Similarly a decrease in the temperature of .the bulbV 12 will` cause .an opening of 'the valve to increase the sup ly of steam. By proper setting of the regal) ing means a predetermined desired temperature may be maintained at the bulb 12;- To thus operate the-regulating valve in response to changes in temperature the movable valve member 13 (Fig. 2) is moved by steam pressure from the su ply line 8, which steam pressure is varied y the temperature fluctuations at the bulb 12. rThe steam for the` operation of the valve member 13 is, in the specific embodiment shownv taken from ipe 8 through the pipe 14 leading to a uid pressure chamber 15 within g the expanding-contracting bellows 16'.

.Steam pressure in the chamber lexpands the bellows downward to press lthe yvalve member 13 toward closed position. The valve' member 13 is movedtoward open position by steam pressure from the su ply line 8, passing" through the o ening 1 to the chamber 18 of the cx an ing-contracting bellows 19 and expan ing these bellows upward, as shown in Fi 2, to lift the valve member 13 away from t e seat 2O.v

In Fig. 2 the valve is shown in its full open position as at the beginning of the heating, when theI steam pressure from line 8 expands bellows 19 and raises the disk 21 carrying valve stem 22 and valve member 13. As the temperature of the tank 6 rises the bulb 12 becomes heated and acts to increase the pressure within the upper bellows 16, which ex ands downward against the disk 21 and, ue to its greater diameter, the bellows 16 compresses the bellows 19 and moves the valve member 13 toward closed position to decrease the How of steam.

This control of the iuid pressure in the bellows 16 thus determines the position of the valve member 13 and re ulates the steam supply. The ipe 14 supp ying the operating pressure rom the main 8 is provided with a reducing or restricting valve 24 comprising an opening 25 controlled in size by the adjustable Aneedle valve 26, adapted to beset to any desired size of opening. Pressure passing through this restricting valve 24 will build up in the bellows 16 to close the main valve 13 unless this pressure is relieved through the by-pass pi e 27 leading to the temperature controlle pilot valve mechanism designated generally by the reference numeral 130 and shown in detail in Fig. 3.

In this pilot valve mechanism (Fig. 3) the bypass 27 leads through the passage 28 to the valve opening 29 controlled by the pilot valve 30. In the usual starting or cool condition of the apparatus the valve 30 is held open by spring 31 so that the steam is free to escape upward around the valve stem 32, which is triangular in section, and throu h the'surrounding chamber 33 into the dischar e pipe or outlet 34 which may waste the ischarge. lVith the bypass 27 thus discharging freely through the pilot valve pressure will not build up in the bellows 16 and the regulating valve 9 will remain open. As the bulb 12 becomes heated it moves the pilot valve 30 toward its seat 29, this being accomplished by expansion of the lluid,`ether for instance, which is hermetically sealed in the bulb 12 and connecting tube 35 and chamber 36 in bellows 37. The expansion of the thermostatic fluid will expand the bellows downward to press the stud 38 of the diaphragm 39"against the end of the pilot valve stem compressing the spring 31 and moving the pilot valve 30 downward to eventually bring the valve 30 so close to its seat 29 that this pilot valve openmnr the valve seat 25 and needle 26 of the restricting valve 24. Then steam pressure will be built up within the bellows `16 and said steam pressure gradually increases throughthe continued expansion of bellows 37 and the consequent restriction of pilot valve 30. As the heating. of bulb 12 continues this closing ofi' of the flow through the pilot relief valve and the resultant throttling of the steam supply through the regulating valve will also continue until the temperature at the bulb 12 ceases to increase and is exactly the temperature to hold the pilot valve 30 and regulating valve 13 in position to supply just enough steam to maintain said temperature constant. Any disturbance el this equilibrium will he followed by an automatic readjustment of 4the apparatus tending te restore it.

lt the temperature of the liquid 7 shows a tendency to drop, the lesser amount of heat then transmitted to bulb 12 causes a reduction in pressure within the thermostatd is less than the opening between expansion of the thermostatic bellows 37 caused the pilot valve 30 to allow less steam to pass at that point, thus building up more steam pressure Within the larger bellows 16 and compressing the smaller bellows 19 enough to cause the regulating valve 9 to pass the lesser amount of steam needed at the tank.

To permit the automatic regulator to be set for any desired predetermined temperature the thermostatic bellows 37 is supported from the base 38 by means of the rods 39, cross pieces 4() and the screw coupling 43 forming an adjustable support between the cross pieces 40 and the bellows 37. By revolving this oupling 43 one end of which `is provided with a right hand thread while the other is provided with a left hand thread, the bellows 37 is moved vertically, being prevented from revolving by the arm 45 which engages one of the rods 39 as illustrated. Thus the bellows 37 will have to expand to a lesser or greater extent to operate the pilot valve 30 dependingon the position to which the coupling 43 'is moved. The setting of the pilot valve is thus indicated on the graduated scale 4l by the pointer 42 fulcruming at 44 and having its end projecting within the groove 46 of the coupling 43.

The pilot valve 30 with its seat `29 makes use of a variable leak or reliel principle to allow an escape of any excess pressure beyond the exact amount needed to operate the regulating valve 9. This pilot valve is therefore not ietween the source of pressure supply and the point of application of the pressure. It is also not necessary that the pilot valve 30 close steam tight to enable an operative pressure to be built up within the steam bellows 16 sulcient to close tight sluit the valve member 13.

When the bulb l2 is not heated, fluid contained within the thermostatie system 12, 35, 36 causes the-bellows 37 to assume a form between a total collapse and Fully expanded condition substantially as shown in Fig. 3 and, consequently, when in werking order the expansion of the spring 3l is notable to push the pilot valve 3G upward above the position shown. The upper valve face 43 of the valve 30 is-thus spaced away from the upper seat 49 a suitable distance to permit free passage of the escaping steam. However, if there is any injury of the bulb off the supply ofsteam. The valve 48, 4:9

thus forms a -safetydevice automatically shutting ofi' the flow of the heating fluid in case the thermostatic system becomes inoperative. This prevents any injury which excessive heating might 'bring about if the failure of the thermostatic system is such as to otherwise cause the valve 9 to remain open or opened from the closed position.

In the form of apparatus as show-n inthe drawings no stuiiing boxes are used in any partof the system. The flexible diaphra m 39', formed of canvas rubber composition or instance, in conjunction with the cylinder tightly sealed at each end by the clamping pressure of the bolts 51 and ring 52 affords a steam tight chamber for the pilot valve 30 without loss of movement due to the friction of a stuiiing box. Similarly each of the bellows 16, 19 and 37 eliminates the friction loss of a stung box at 'its location and the bellows 19 also takes the place of aspring for definitely openin vthe re ulating valve 9 and securing smoot operatlon. The bellows 19 is also elective in compensating for variation in the pressure of the steam supply on the line 8. Ordinarily and without the bellows 19 or its equivalent if the steam pressure supplied through pipe 8 varies, the same amount of ,opening of the valve 9 admits greater or less heat as the steam pressure is higher or lower and this calls upon the automatic regulator to follow up such changes and each time the regulator has to work against a different pressure condition in the line 8 which would indirectly alter the setting of the regulator. In the .case of this inventiomhowever, as the steam pressure 1n supply line 8 varies a corresponding lesser or greater pressure is supplied through the restricting valve 24 for operating the larger steam bellows 16 and the effect of this 1s compensated for by the lesser or greater resistance offered by the opposing steam bellows 19 so that the eli'ect of the variation is negligible. v l

The inclusion of the restricting valve 24 ,permitsthe use of a minimum amount of steam forthe o eration of the valve 9, avoiding waste an minimizing the necessary movement of the pilot valve 30. Furthermore the restricting valve 24 may be so adjusted that enough steam is available for expanding the larger bellows 16 'as promptly as required but still `restricting the steam through the pipe 14 to such an amountthat the smaller bellows` 19 can also expand romptly when necessary, the ressure with- 1n the bellows'l being quick y reduced by the opening of the pilot valve 30.

The particular form' of apparatus shown in the drawings is simply by Way of illustration of one means of arranging the elements of the system. In Figs. 1 and 2 the bellows 16 and 19 are shown asv supported from the bonnet 55 of the casing of valve 9, a lower disk 56 with the bellows 19 being connected by bolts 57 to the upper supporting disk 58 for the bellows 16. It is obvious that any other means for supporting the bellows in position of the relation to each other and the valve 9 could be used.

In the form of the movable valve member 13 shown inv Fig. 2 the steam passing through between the valve member and its seat 20 olers a diminishing resistancev as the disk approaches closer to the seat 2() 'due to the drop in pressure below the disk. This tends to 'cause the valve 13 of Fig. 2 to open and close quickly. Instead of this disk form of valve a balanced valve of the piston type for instance, may beused or, as shown in Fig. 1, a form of valve may be used in which the flow is in a reverse direction between i the valve disk and its seat so that the valve will oiier an increasing resistance as it approaches its seat due to the drop in pressure above the disk. In this Fi/g. 4 form of valve the valve disk l59 is above its seat 60 and the valve stem 61 is hollow providing a passage 62 for the steam from the line 8 to the interior chamber 63 of the smaller bellows 64. The valve f stem where it passes through the bonnet bushing 65`is surrounded by a stuliing box containing the packing material 66 sealing the parts against the escape of steam. The bellows 64 are supported b a screw thread lianged cap 67 screw threa ed on to the upper end of the bushing 65. By this apparatus thesteam ressure of the sup y line 8 is continuous y maintained lwit in the bellows 64 so that these bellows expand upward. The upper larger bellows 16 are su ported :from the disk 68 by rods 69 lfrom t e disk 70 supported by the bushin 65, steam being supplied to this upper be lows by a pipe 14 as in Figs. 1 and 2.

For certain conditions it is desirable to use a. bulb more sensitive to Vtemperature changes than the structure" shown at 12 in Fig. 3, withopt making the bulb extremely long. In such la case the bulb structure .shown in Figs. 5, 6 and 7 `may be used in which 71 represents an outer wall andl 72 an .inner walll of a bulb made up of two pieces of tubing, one within the other and Joined at one end and closed by a suitably attached rin 73 while their other endsrare joined and c osed by ring 74.' The conduit 35' is supported by the bridge 7 5 within the open circulation space left within the inner yWithin the scope of the appended claims.

wall 72. The end of the conduit 35 is 3. In a temperature control system the joined to the branch 76, each end of which combination with a part to be heated and projects into the closed space` Within the means for supplying a heating fluid thereto, outer and inner Walls 71 and 72. This form of means for regulating the supply of the of bulb exposes a thin layer of contained lheating fluid comprising a valve operated fluid for penetration of temperature changes by the pressure of the heating fluid includboth along the outer Wall 7l and the inner ing differential pressure operated members wall 72 so that a very extensive exposure of both supplied With fluid pressure from the the thermostatic fluid is attained in a comsame side of said valve and working against paratively short bulb. `atmospheric pressure, and a thermostatically The showing of the apparatus in the actuated pilot valve controlling said operatdrawings is mainly diagrammatic in charing pressure. acter, and it is obvious that various'modifi- 4. In a temperature control system the cations and changes may be resorted to combination with a part to be heated and Without departing from the principle of the means for supplying a heating fluid thereto,

invention, the steam containing passages and of means for regulating the supply of the chambers may, of course, be enclosed or heating fluid comprising a valve, fluid pres jacketed Where desired and the various parts sure operated means for moving said valve of the s stem will be arranged most suitably including differential pressure operated with re ation to each other depending upon members both supplied with fluid pressure the s ecial characteristics of each individuali from the same side of said valve and Workinsta lation. While the disclosure shows a y ing against atmospheric pressure, and means system in which a restricting valve 24 is in`` for supplying said heating fluid to said terposed between the pressure source 8 and `operating means for said valve comprising the pilot valve 30, it is obvious that the pres-4 a thermostatic control adapted to vary the sure in the bellows 16 may likewise be con-'lf operating pressure to control the position of trolled by interchanging the relative posi-lsaid valve.

tions of the restricting valve and thermo-2., y5. In a temperature control system the statically controlled pilot valve, and in such lcombination with a part to be heated and case it Would probably be preferable to have means for supplying a heating fluid thereto. the pilot valve open as the temperature inof means for regulating the supply of the creases so as to build up pressure in the bel-,l heating fluid comprising a valve, fluid presloivs 16, said pressure being held by the "sure operated means for moving said valve small opening of the restricting valve. A v,comprising oppositely disposed pressure lowering of' the temperature will corre- Loperated members disconnected from each spondingly close the pilot valve and the per-` other in the full open position of the valve. manently open restricting and discharge and means for supplying said heating fluid valve will continue to discharge steam to reto said operating means for said valve comduce the fluid pressure in the bellows 16. l prising a flow restricting connection and The invention isnot confined to the spea thermostatically controlled pilot valve cilicembodiments shown and described but adapted to vary the operating pressure to is intended to cover all modifications falling control the position of said main valve.

6. In a temperature control system the `I claim: combination with a regulating valve for l. In a temperature control system the heating fluid, of means for operating said combination with a part to be heated and valve comprising a fluid pressure moved means for supplying a heating fluid there member connected to said valve and adapted to, of means for regulating the supply of to hold said valve open, and a second fluid the heating fluid comprising a valye operpressure moved element normally disengaged ated by the pressure of the heating fluid infrom and out of contact with said first prescludiug differential pressure operated memsure moved element, and adapted to move bers both suppliedewith fluid pressure from thereagainst to close said valve.

the same side of said valve and Working 7. In a temperature control system the against atmospheric pressure. combination with a regulating valve for 2. In a temperature control system the heating fluid` of means for operating said combination with a part to be heated and valve comprising a fluid pressure moved means for supplying al heating fluid thereto, member connected to said valve and adapted nl means for regulating the supply of the to hold said valve open, and a second fluid heating fluid comprising a valve operated by pressure moved element, normally disenthe pressure of the heating fluid including gaged from said first pressure moved eledifferential pressure operated members both ment, and adapted to move thereagainst to supplied with fluid pressure from the same close said valve, each of said elements being side of said valve and working against atoperated by the pressure of the heating mospheric pressure, and a thermostatic confluid on'the same side of said valve.

trol for said operating pressure. 8. In a temperature control system, a

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main regulating valvev and liuid pressure means for operating said valve comprising an automatic re lator having a thermostatic bulb, anexpan ing contracting member connected to said bulb, a diaphragm member engaged by said expanding contracting' member, a pilot valve actuated by sald diaphragm member for discharging Huid pressure, and means for supplyingiiuid pressure through a predetermined opening -for operating said main valve. f

9. ln a temperature control system, a

' main valve for regulating the iiow of a heat-A ying tluid, fluid pressure means for operating said main valve, a fixed openin orthe supply of duid pressure from t e source of heating duid, a pilot valve for varying said duid pressure, and a thermostat means for controlling said pilot valvev comprising an expansible contractible member, and a fdiaphragm member carrying said pilot valve and engaged by said expansible contractible member.

l0. lln a temperature lcontrol system, a main valve for re lating the supply of ay heating tluidLflui pressure means for operating said main valve, a fixed opening for a supply of Huid pressure from the. source oi heating duid, therinostatically` controlled means for regulating the operating pressure" pressure means comprising l2. In a regulatingvsystem havin amain valve for regulating the supply o heating Huid and means for actuating said main valve by fluid pressure from a given' source, a second fluid pressure operated means ac, tuated -from the same source offiuid pressure and adapted to oppose said firstl named o erating means in accordance withjpressure c anges in said luid pressure,'each of sald valve for regulatm fluid pressure operated means having at mospheric ressure opposing the fluid pressure from t e source of'rheating fluid..

13. In a regulating system having a main valve for regulating the supply of heating fluid and means for actuatin said main valve by fluid pressure from t e' source of heating iiuid, a second lfluid pressure operat` ed means actuated from the same source of fluid pressure and adapted. to oppose said rst named operating means in accordance with pressure changesfin said duid pressure, 'each of= said fluid pressure operated means having atmospheric pressure opposing the pressure yirorn the source oit heating 14:. A regulatin system includin a main the supply o a iluid under pressure, lui pressure means 'for actuating said main valve, a iixed opening for the supply of `iiuid pressure to said operating means from the samesource as said duid under pressure, a connection fromsaid duid under pressurey to an ex ending contracting member, and a pilot va ve adapted to vary the iuid pressure in said operating means and control the position of said main valve, said main valve being automatically closed cornes` inoperative in any position. l

15.0In.' a` temperature control system the combination with a part to be heated, of

means for su plying a heating huid there to a main va ve for regulatinfr the supplyv of heating iuid, iiuid preiire operated .means or'operating said main valve', and

' 16., In a thermostatic control a thermome' ter bulb comprising a hollow cylindrical chamber having exterior and interior exosed Walls, and a connecting pipe extending from end lto end through the hollow portion of said bulb.I

HERBERT fxnn.

when said expanded contracted member be- 

